Dispenser stick

ABSTRACT

The invention relates to a dispenser stick ( 1 ) for storing and applying a pasty gradually removable stick compound from a cosmetic or otherwise product, such as for example a deodorant stick or glue stick. Said dispenser stick is provided with a cylindrical housing ( 1 ′) comprising an upper dispensing opening, a closure cap ( 2 ) that hermetically seals the dispensing opening via a sealing lip ( 5 ), and a feeding plunger ( 7 ) that can be axially displaced inside the housing ( 1 ′). The dispenser stick ( 1 ) is characterized in that the feeding plunger ( 9 ) can only be displaced towards the dispensing opening and is blocked in the opposite direction and in that the closure cap ( 2 ) is configured as a double-walled structure that has an interior cap ( 3 ) that can be axially displaced relative to the closure cap ( 2 ). Advantageously, the housing ( 1 ′) is double-walled with an exterior housing ( 9 ) that can be closed together with the closure cap ( 2 ) and with an interior housing ( 6 ) accommodating the stick compound, which can be displaced axially in the exterior housing ( 9 ).

The invention concerns a dispenser stick for storing and applying apasty dispensable stick compound that consists of a cosmetic product orsome other type of product, for example, a deodorant stick or gluestick, which comprises a stick-shaped housing with an upper dispensingoutlet, a closure cap that seals the dispensing outlet airtight by meansof a sealing lip, and a feeding plunger that can be moved axially insidethe housing.

Dispenser sticks for applying a pasty dispensable product, for example,deodorant sticks or glue sticks, are known in various designs. Dispensersticks in which the stick compound is used by moving it upward out ofthe dispensing outlet by a supporting plunger by means of a rotatingbase with a spindle or by a pushing device are widely used. To use thistype of dispenser stick, the closure cap must first be removed and thenthe plunger must be pushed up. Accordingly, two separate manualoperations are necessary to place the dispenser stick in a position forapplying it.

To create a dispenser stick that has a simpler design and is easier touse, German Utility Patent GM 76 13 989 proposes that the closure cap besealed against the housing by means of a sealing lip in such a way that,when the closure cap is removed, the stick compound is pushed a certaindistance out of the housing by the negative pressure produced by theremoval of the cap. A rotating spindle or a pushing device is no longernecessary. The only function of the plunger as a feeding plunger is toprovide an airtight seal of the stick compound towards the bottom.

A disadvantage of this previously known dispenser stick is that thestick compound is pushed back into the housing during its application.The only resistance to the stick compound being pushed back into thehousing is the static friction of the feeding plunger and, depending onthat, the static friction of the stick compound on the inside wall ofthe housing as well. This static friction may not be too great, either,because it must be possible, even if the stick compound that has beenpushed out is not used, to screw the closure cap back onto the housing,at which time the protruding stick compound is pushed back into thehousing. In this regard, when the stick compound is pushed back into thehousing, it is unavoidable that the stick compound is forced out to theside at the upper edge of the housing.

Proceeding from this prior art, the objective of the invention is todesign a dispenser stick of the specified type in such a way that,despite continued simple design and handling, the disadvantage of thestick compound being pushed back into the housing is eliminated.

This objective is achieved with the characterizing features of claim 1,according to which the feeding plunger can be moved only towards thedispensing outlet and is locked in the opposite direction, and theclosure cap is designed with a double wall with an inner cap that can beaxially displaced relative to the closure cap. Advantageousmodifications of the invention are specified in the dependent claims.

The locking of the feeding plunger in the direction opposite thedispensing direction in accordance with the invention advantageouslyprevents the stick compound from being pushed back into the housing asthe stick compound is being applied, during which axial pressure on thestick compound is unavoidable. This locking of the feeding plunger isaccomplished, for example, by mounting a retaining spring below thefeeding plunger. The retaining spring catches on the inside wall of thehousing and is designed in such a way that axial displacement in thedispensing direction remains possible.

Alternatively, in accordance with an advantageous modification of theinvention, the inside wall of the housing can be provided with fineserration or with fine locking grooves, in which the correspondinglydesigned feeding plunger catches to lock it in the direction oppositethe dispensing direction.

Since the stick compound that has been pushed out of the housing forapplication can no longer be pushed back into the housing, but it mustbe possible to close the dispenser stick even with unused stick compoundthat has been pushed out, in accordance with the invention, the closurecap is designed with a double wall and an inner cap. As the closure capis being screwed onto the housing, the inner cap sets down on theprotruding stick compound and is then pushed axially into the closurecap as the screwing operation continues. The inner cap is connected withthe closure cap by a spring element in such a way that it is supported,so that when the cap is unscrewed again, initially only the closure capand then the inner cap are axially displaced due to the spring tensionthat was previously produced.

In an advantageous modification of the invention, both the closure capand the housing have a double-walled construction. An axiallydisplaceable inner housing, which extends from the top of the outerhousing and serves to hold the stick compound, is mounted inside theouter housing, which can be closed with the closure cap. The length ofthe part of the inner housing that extends from the outer housingcorresponds to the length of the inner cap, so that when the closure capis screwed on, the upper base of the inner cap rests on the upper edgeof the inner housing, and the lower edge of the inner cap rests on theupper edge of the outer housing.

A crucial advantage of this double-walled design of the housing is seenduring the filling of the inner housing with the stick compound, whichis usually still liquid at this point. The inner housing, which ispushed only partially into the outer housing during the fillingoperation, is pushed completely into the outer housing after the fillingoperation has been completed and the stick compound has hardened, andthe stick compound and the feeding plunger, which rests on a centralprojection of the base of the housing, remain unchanged in theirposition. This causes the stick compound to be pushed within the innerhousing towards the dispensing outlet, so that the stick compoundbecomes detached from the inner wall of the inner housing. The usualadhesion of the stick compound to the inner wall of the housing thatoccurs during the filling operation in previously known dispenser sticksis thus successfully prevented before the first use despite theconventional filling operation, and the stick compound can then beeasily advanced even during its first use.

The advancing of the stick compound in the dispenser stick of theinvention to allow it to be applied occurs indirectly by the productionof a negative pressure between the inner cap and the inner housing whenthe closure cap is screwed on. For this purpose, the upper projectingregion of the inner housing is provided with an outwardly projectingannular sealing lip, which, when the closure cap has been screwed on,rests against the inner wall of the inner cap and produces a seal. Inthis regard, a cavity formed between the inner housing and the inner capis sealed towards the bottom by the sealing lip. When the closure cap isunscrewed and the inner cap is moved axially upward in the dispensingdirection, this cavity becomes larger, and the resulting negativepressure “pulls” the column of stick compound a small distance upwardout of the dispensing outlet. The possible amount of this axialdisplacement of the stick compound is adjusted in advance by suitableshaping of the annular cavity between the inner cap and the innerhousing.

In accordance with the invention, the sealing lip is mounted at adownward angle on the inner housing in such a way that it acts as acheck valve, and when the outer housing is closed by the closure cap,the resulting positive air pressure inside the diminishing annularcavity is relieved to the outside by venting via the sealing lip.

Further advantages, features, and properties of the invention,especially the manner of operation of the dispenser stick of theinvention, are explained in greater detail below with reference to thespecific embodiments illustrated in the drawings.

FIG. 1 shows a dispenser stick in an exploded view.

FIG. 1 a shows details of FIG. 1.

FIG. 2 shows the dispenser stick of FIG. 1 in its assembled, open state.

FIGS. 3 a to 3 c show vertical sections of the dispenser stick of FIG. 1in different positions of use.

FIG. 4 shows a vertical section of the dispenser stick of FIG. 1, filledin the initial position.

FIGS. 4 a and 4 b show two different enlarged partial sections of FIG.4.

FIGS. 5 to 9 show vertical sections of the dispenser stick of FIG. 1 indifferent positions of use.

FIG. 10 shows a vertical partial section of a dispenser stick withserration for locking the plunger.

FIGS. 11 to 13 show the housing of the dispenser stick of FIG. 1 indifferent filling positions.

FIG. 14 shows a vertical partial section of a dispenser stick with thehousing base opened.

The exploded view in FIG. 1 shows the individual parts of a dispenserstick 1 of the invention in their order of assembly. The enlarged viewin FIG. 1 a shows details of the feeding plunger 7 and the retainingspring 8. FIG. 2 shows the assembled housing 1′, from which the stickcompound 10 has emerged. The closure cap 2 can be screwed onto thehousing 1′.

The housing 1′ of the dispenser stick consists of an outer housing 9,which is closed at the bottom and into which the longer inner housing 6can be inserted from above. The inner housing 6 has a tubularconstruction, so that the feeding plunger 7 with the retaining springmounted below it can be inserted through the open lower end. The upperregion of the inner housing 6 that projects above the outer housing 9 isformed with two annular webs 15, between which the downwardly angledsealing lip 5 is mounted. Below the annular webs 15, the lower end ofthe inner housing 6 is provided with additional annular webs 16 a, 16 b,16 c, which support the inserted inner housing 6 against the outerhousing 9. The upper part of the outer housing 9 is provided with anexternal thread 11, onto which the closure cap 2 with the insertedhelical spring 4 and inner cap 3 is screwed to close the dispenser stick1.

FIGS. 3 a to 3 c each show front elevations of the dispenser stick 1 andthe housing 1′ in different positions of use. FIG. 3 a shows thedispenser stick 1 with the closure cap 2 screwed on in its initialposition before use. In FIG. 3 b, the closure cap 2 has been unscrewedby the distance x, which, as shown in FIG. 3 c, has caused the stickcompound 10 to be brought out of the housing 1′ and the inner housing 6by about the same distance x. The closure cap 2 is completely removedfrom the outer housing 9, and the stick compound 10, which has beendisplaced towards the outside with the aid of the sealing lip 5, can bedispensed and applied.

FIG. 4 shows the dispenser stick 1 with the closure cap 2 screwed on ina vertical section that corresponds to FIG. 3 a. To provide a betterview, the important upper and lower regions of FIG. 4 are shown inenlarged partial sections in FIGS. 4 a and 4 b, respectively. In FIGS.4, 4 a, and 4 b, the individual parts that constitute the dispenserstick 1 (see also FIGS. 1 and 2 in this regard) are assembled and readyto use. In the illustrated initial position, the feeding plunger 7 withthe retaining spring 8 mounted below it is located directly above acentral projection 23 of the base 17 of the outer housing 9 with thestick compound 10 filling the space above it. The lower annular web 16 cof the inner housing 6 rests on the base 17 of the outer housing 9, andthe inner housing 6 is connected with the outer housing 9 in a snapconnection by means of the web 16 c and an annular bead 24 of the outerhousing 9. The inner housing 6 is supported against the outer housing 9by this web 16 c and by the two upper annular webs 16 a and 16 b. Theclosure cap 2 is completely screwed on, and the inner cap 3, supportedby the helical spring 4, rests with its lower edge 18 on the upper edge19 of the outer housing 9 and with its upper base 20 on the upper edge21 of the inner housing 6. The dispensing outlet 13 (cf. also FIG. 2)formed by the upper edge 21 is thus sealed airtight by the inner cap 3.The inside diameter of the upper projecting part of the inner cap 3 isapproximately the same as the outside diameter of the inner housing 6,and the inner cap 3 expands in a step, so that the outside diameter ofits lower part approximately matches the inside diameter of the closurecap 2. The step 22 formed by this expansion serves as a seat for thehelical spring 4 inserted in the closure cap. At the same time, the step22, together with the sealing lip 5, forms a cavity 12 that is sealedtowards the bottom, enlarges when the closure cap 2 is screwed on, andproduces the negative pressure necessary for “pulling” the stickcompound up by suction. In FIGS. 5, 6, and 7, this process of “pulling”the stick compound up by suction is illustrated separately in verticalsections.

In FIG. 5, the closure cap 2 of the dispenser stick 1 has been unscrewedby the distance x relative to the initial position shown in FIG. 4. Thisenlarges the cavity 12, as shown, and the resulting negative pressurecauses the stick compound 10 to be pulled out of the inner housing 6 bythe amount x. In the illustrated position, the sealing lip 5 has reachedthe lower end of the inner cap 3, so that when the closure cap 2 isfurther unscrewed, the cavity 12 is vented, and the stick compound 10remains in the position that it has reached.

In FIG. 6 (corresponding to FIG. 3 c), the closure cap 2 is completelyremoved from the inner housing 6, and the stick compound 10, whichextends above the upper edge 21 of the inner housing 6 by a distance x,can be dispensed.

As FIG. 7 shows, after the stick compound 10 has been dispensed, theclosure cap 2 is screwed partially back onto the outer housing 9, andthe sealing lip 5 makes sealing contact with the inner housing 6. As theclosure cap 2 is screwed on further, and the cavity 12 becomes smaller,the positive pressure that develops in the cavity 12 is relieved to theoutside by the sealing lip 5, which is mounted at a downward angle.

FIGS. 8 and 9 serve to illustrate the function of the double-walledclosure cap 2. In the case illustrated here, the stick compoundprotruding from the inner housing 6 has not been completely dispensed orused. As the closure cap 2 is screwed on, the inner cap 3 is first moveddown until its upper base 20 rests on the stick compound 10. Thisposition is shown in FIG. 8. As the closure cap 2 is further screwed on,the inner cap 3 can no longer follow its downward path, because theretaining spring 8 arrests the feeding plunger 7, so that the stickcompound 10 cannot be pushed down. The inner cap 3 remains in itsposition and is axially displaced within the closure cap 2 against thespring tension of the helical spring 4, as is shown in FIG. 9. Theannular cavity 12 remains unchanged during this operation, and thesealing lip 5 remains at the lower edge 18 of the inner cap 3. When theclosure cap 2 is unscrewed again, the helical spring 4 causes the innercap 3 to remain in its position at first. Due to the illustratedposition of the sealing lip 5, negative pressure is no longer producedduring the subsequent displacement of the inner cap 3, and furtherupward movement of the stick compound 10 is prevented.

In the dispenser stick 1 of FIGS. 1 to 9, the locking effect on thefeeding plunger 7 was produced by a retaining spring 8 mounted below thefeeding plunger 7. In accordance with the invention, however, thislocking effect can also be produced solely by a feeding plunger 7 withan inner housing suitably adapted to achieve this effect. In FIG. 10,which shows the lower part of the housing 1′ of a dispenser stick 1 withouter housing 9 and stick compound 10 in an enlarged vertical partialsection, the inner wall of the inner housing 6′ is designed with annularfine serration 14. The lateral edges of the feeding plunger 7 catch inthis serration in such a way that axial displacement of the feedingplunger 7 is possible in the dispensing direction but not in theopposite direction.

In accordance with the invention, the housing 1′ of the dispenser stick1 can have a double-walled design. The principle on which this housingdesign is based for simple filling with stick compound 10 will now beexplained in greater detail with reference to FIGS. 11 to 13. FIG. 11shows a vertical section of the dispenser stick 1 without its closurecap 2 before it has been filled with the stick compound. The innerhousing 6 has been inserted in the outer housing 9 as far as the annularweb 16 b, so that the lower web 16 c is located some distance above thebase 17 of the outer housing 9 on an annular bead 24 of the outerhousing 9, and the feeding plunger 7 rests on the central projection 23of the housing base 17. In this position, the stick compound 10 ispoured in from above, and the filling ends a certain distance below theupper edge 21 of the inner housing 6, as shown in FIG. 12. Then, asshown in FIG. 13, after the stick compound 10 has hardened, the innerhousing 6 is pushed farther into the outer housing 9, so that the upperannular web 16 a is also pushed into the outer housing 9, and now thelower annular web 16 c rests on the housing base 17 below the annularbead 24. This causes the inner housing 6 to lock with the outer housing9 in a snap connection prevents undesired upward movement of the innerhousing 6 when negative pressure is present in the cavity 12. Since thestick compound 10 cannot follow this movement due to the blocking of thefeeding plunger 7, which rests on the central projection 23 of thehousing base 17, the stick compound 10 is displaced inside the innerhousing 6 as far as the upper edge 21. The stick compound 10, whichpossibly sticks to the inner wall of the inner housing 6 as a result ofthe filling operation, is thus detached from the inner wall and can thenbe easily moved even during its first use.

To ensure that the inner housing 6 can be inserted into the outerhousing 9 as far as the housing base 17 after the filling operation hasbeen completed, while the position of the feeding plunger 7 remainsunchanged, in the embodiment shown in Figures 11 to 13, the feedingplunger 7 rests in the filled position on a central projection 23 of thehousing base 17 some distance above the housing base 17. Alternatively,however, it is also possible, in accordance with the invention, as isshown in the vertical partial section of FIG. 14, to provide an annularhousing base 17′ of the outer housing 9′ with a central opening 25 andelimination of the central projection 23. In this case, the separationof the feeding plunger 7 from the housing base 17′ that is required forthe filling operation is provided by an annular web 27, which turns upat the lower edge 26 of the central opening 25 and serves as a supportfor the feeding plunger 7. The advantage of this alternative design ofthe outer housing 9′ with a housing base 17′ that is open at the bottomis that the feeding plunger 7 is accessible from the outside through thecentral opening 25. If, for example, the sealing lip 5 is damaged byimproper use, so that negative pressure for dispensing the stickcompound 10 can no longer be produced, a long object can be insertedthrough the open base of the outer housing 9′ to push up the feedingplunger 7 and thus the stick compound 10.

The invention is not limited to the illustrated embodiments but rathercan be constructed in a variety of ways with respect to the design andthe individual required components of the dispenser stick as long as thefeatures of the invention of a double-walled design of the closure capand a design of the feeding plunger with a reverse movement arrestingmechanism are retained.

LIST OF REFERENCE NUMBERS

-   1 dispenser stick-   1′ housing of 1-   2 closure cap of 1-   3 inner cap-   4 helical spring-   5 sealing lip-   6, 6′ inner housing-   7 feeding plunger-   8 retaining spring-   9, 9′ outer housing-   10 stick compound-   11 external thread-   12 cavity-   13 dispensing outlet-   14 annular serration-   15 annular webs-   16 a-16 c annular webs-   17, 17′ housing base-   18 lower edge of the inner cap 3-   19 upper edge of the outer housing 9-   20 upper base of the inner cap 3-   21 upper edge of the inner housing 6-   22 step-   23 central projection-   24 annular bead-   25 central opening-   26 inner edge of the central opening 25-   27 annular web-   x displacement distance (stick compound, inner cap)

1. Dispenser stick (1) for storing and applying a pasty dispensablestick compound (10) that consists of a cosmetic product or other type ofproduct, for example, a deodorant stick or glue stick, which comprises astick-shaped housing (1′) with an upper dispensing outlet (13), aclosure cap (2) that seals the dispensing outlet (13) airtight by meansof a sealing lip (5), and a feeding plunger (7) that can be movedaxially inside the housing (1′), wherein the feeding plunger (7) can bemoved only towards the dispensing outlet (13) and is locked in theopposite direction, and the closure cap (2) is designed with a doublewall with an inner cap (3) that can be axially displaced relative to theclosure cap (2).
 2. Dispenser stick (1) in accordance with claim 1,wherein the housing (1′) has a double-walled design with an outerhousing (9) that can be closed with the closure cap (2) and with aninner housing (6) that can be axially displaced in the outer housing (9)and serves to hold the stick compound (10).
 3. Dispenser stick (1) inaccordance with claim 1, wherein the inner cap (3) is elasticallyconnected with the closure cap (2) in the axial direction by means of aspring element, for example, a helical spring (4).
 4. Dispenser stick(1) in accordance with claim 1, wherein the axial movement of thefeeding plunger (7) in the direction opposite the dispensing directionis blocked by a retaining spring (8) that catches on the inner wall ofthe inner housing (6).
 5. Dispenser stick (1) in accordance with thatclaim 1, wherein the axial movement of the feeding plunger (7) in thedirection opposite the dispensing direction is blocked by annular fineserration (14) provided on the inner wall of the inner housing (6) or byfine locking grooves in which the feeding plunger (7) catches. 6.Dispenser stick (1) in accordance with claim 1, wherein the upper regionof the inner housing (6) is provided with an outwardly projectingannular sealing lip (5), which, when the closure cap (2) has beenslipped onto or screwed onto the outer housing (9), presses against theinner wall of the inner cap (3) to produce a seal.
 7. Dispenser stick(1) in accordance with claim 6, wherein the sealing lip (5) seals anannular cavity (12) between the inner cap (3) and the inner housing (6)in such a way that, when the closure cap (2) has been removed and thecavity (12) has been increased in size as a result of the removal of theclosure cap (2), a negative pressure is produced in the cavity (12),which negative pressure is sufficiently great to advance the stickcompound (10) a predetermined distance (x) out of the dispensing outlet(13) of the inner housing (6).
 8. Dispenser stick (1) in accordance withclaim 7, wherein the amount of axial displacement (x) of the stickcompound (10) can be adjusted in advance by suitable shaping of theannular cavity (12) between the inner cap (3) and the inner housing (6).9. Dispenser stick (1) in accordance with claim 6, wherein the sealinglip (5) is mounted at a downward angle on the inner housing (6) in sucha way that it acts as a check valve, and when the outer housing (9) isclosed by the closure cap (2), the resulting positive air pressureinside the diminishing annular cavity is relieved to the outside byventing via the sealing lip (5).
 10. Dispenser stick (1) in accordancewith claim 2, wherein to fill the dispenser stick with the stickcompound (10) in the filling position of the housing (1′), the feedingplunger (7) and the inner housing (6) are located some distance abovethe housing base (17), such that a lower web (16 c) of the inner housing(6) rests on an annular bead (24) of the outer housing (9), and theinner housing (6) is supported against the outer housing (9) by means ofthe web (16 c) and an upper annular web (16 b).
 11. Dispenser stick (1)in accordance with claim 10, wherein in the filling position of thehousing (1′), the feeding plunger (7) rests on a central projection (23)of the housing base (17).
 12. Dispenser stick (1) in accordance withclaim 10, wherein the housing base (17′) has an annular design with acentral opening (25), whose inner edge (26) is turned up with an annularweb (27), on which the feeding plunger (7) is supported in the fillingposition.
 13. Dispenser stick (1) in accordance with claim 11, whereinafter the filling of the housing (1′) with the stick compound (10) hasbeen completed, the inner housing (6) is pushed completely into theouter housing (9) until it reaches the housing base (17), while theposition of the feeding plunger (7) remains unchanged, and that duringthis operation, the stick compound (10) becomes detached from the innerwall of the inner housing (6).
 14. Dispenser stick (1) in accordancewith claim 13, wherein the web (16 c) of the inner housing (6) is movedover the bead (24) of the outer housing (9), thereby causing the innerhousing (6) to lock with the outer housing (9) in a snap connection,which prevents subsequent upward movement of the inner housing (6) whennegative pressure is present in the cavity (12).